When you reply to someone (and therefore their username is in your tweet) it will appear in their 'mentions' tab (the @username tab on the right hand side).
The location on twitter is usually the place where the page's holder lives.
Contact the pizza store across twitter if they have a page and place an order.
The unconditioned response.
An exaggerated response takes place. Hyporeflexic is when the response is less than average.
You write your message in the same place that you send normal tweets (the big white box at the top of the page). Start your tweet with the persons username (@username)
That is totally up to you if you want to put your number on Twitter. I would advise against it, though. Twitter is a very public place and giving out personal information such as your number is not a very safe practice.
It's a problem with t-mobile not Twitter. There may be a parental lock in place.
There isn't a page that shows you who you've sent requests to. You can only send a request to someone with a private account. If you go back to their profile it will say "request sent" in place of the follow button.
Try Twittad. It has services for advertisers and Twitter users who want to monetize their accounts. Just be sure to read it thoroughly. http://www.twittad.com/ -KS
Myspace, Facebook & Twitter, but Myspace's slogan is "A Place for Friends".
There isn't a specific place to get these - people usually make them themselves.